let currRenderDom = null
let currelRectification = ''
let currelRectificationLevel = ''
let resizeListener = null
let timer = null
let currScale = 1
let isAutofitRunnig = false
let isElRectification = false

function init (options = {}, isShowInitTip = true) {
  if (isShowInitTip) {
    console.log(
      `%c` + `autofit.js` + ` is running`,
      `font-weight: bold; color: #ffb712; background:linear-gradient(-45deg, #bd34fe 50%, #47caff 50% );background: -webkit-linear-gradient( 120deg, #bd34fe 30%, #41d1ff );background-clip: text;-webkit-background-clip: text; -webkit-text-fill-color:linear-gradient( -45deg, #bd34fe 50%, #47caff 50% ); padding: 8px 12px; border-radius: 4px;`
    )
  }
  const {
    dw = 1920,
    dh = 929,
    el = typeof options === 'string' ? options : '#app',
    resize = true,
    ignore = [],
    transition = 'none',
    delay = 0
  } = options
  currRenderDom = el
  let dom = document.querySelector(el)
  if (!dom) {
    console.error(`autofit: '${el}' is not exist`)
    return
  }
  const style = document.createElement('style')
  const ignoreStyle = document.createElement('style')
  style.lang = 'text/css'
  ignoreStyle.lang = 'text/css'
  style.id = 'autofit-style'
  ignoreStyle.id = 'ignoreStyle'
  style.innerHTML = `body {overflow: hidden;}`
  dom.appendChild(style)
  dom.appendChild(ignoreStyle)
  dom.style.height = `${dh}px`
  dom.style.width = `${dw}px`
  dom.style.transformOrigin = `0 0`
  keepFit(dw, dh, dom, ignore)
  resizeListener = () => {
    clearTimeout(timer)
    if (delay != 0)
      timer = setTimeout(() => {
        keepFit(dw, dh, dom, ignore)
        isElRectification &&
          elRectification(currelRectification, currelRectificationLevel)
      }, delay)
    else {
      keepFit(dw, dh, dom, ignore)
      isElRectification &&
        elRectification(currelRectification, currelRectificationLevel)
    }
  }
  resize && window.addEventListener('resize', resizeListener)
  isAutofitRunnig = true
  setTimeout(() => {
    dom.style.transition = `${transition}s`
  })
}
function off (el = '#app') {
  try {
    isElRectification = false
    window.removeEventListener('resize', resizeListener)
    document.querySelector('#autofit-style').remove()
    document.querySelector(currRenderDom ? currRenderDom : el).style = ''
    isElRectification && offelRectification()
  } catch (error) {
    console.error(`autofit: Failed to remove normally`, error)
    isAutofitRunnig = false
  }
  isAutofitRunnig &&
    console.log(
      `%c` + `autofit.js` + ` is off`,
      `font-weight: bold;color: #707070; background: #c9c9c9; padding: 8px 12px; border-radius: 4px;`
    )
}

function elRectification (el, level = 1) {
  if (!isAutofitRunnig) {
    console.error('autofit.js：autofit has not been initialized yet')
  }
  !el && console.error(`autofit.js：bad selector: ${el}`)
  currelRectification = el
  currelRectificationLevel = level
  const currEl = document.querySelectorAll(el)
  if (currEl.length == 0) {
    console.error('autofit.js：elRectification found no element')
    return
  }
  for (let item of currEl) {
    if (!isElRectification) {
      item.originalWidth = item.clientWidth
      item.originalHeight = item.clientHeight
    }
    let rectification = currScale == 1 ? 1 : currScale * level
    item.style.width = `${item.originalWidth * rectification}px`
    item.style.height = `${item.originalHeight * rectification}px`
    item.style.transform = `scale(${1 / currScale})`
    item.style.transformOrigin = `0 0`
  }
  isElRectification = true
}
function offelRectification () {
  if (!currelRectification) return
  for (let item of document.querySelectorAll(currelRectification)) {
    item.style.width = ``
    item.style.height = ``
    item.style.transform = ``
  }
}
function keepFit (dw, dh, dom, ignore) {
  let clientHeight = document.documentElement.clientHeight
  let clientWidth = document.documentElement.clientWidth
  currScale =
    clientWidth / clientHeight < dw / dh ? clientWidth / dw : clientHeight / dh
  dom.style.height = `${clientHeight / currScale}px`
  dom.style.width = `${clientWidth / currScale}px`
  dom.style.transform = `scale(${currScale})`
  for (let item of ignore) {
    let itemEl = item.el || item.dom
    typeof item == 'string' && (itemEl = item)
    if (!itemEl) {
      console.error(`autofit: bad selector: ${itemEl}`)
      continue
    }
    let realScale = item.scale ? item.scale : 1 / currScale
    let realFontSize = realScale != currScale ? item.fontSize : 'autofit'
    let realWidth = realScale != currScale ? item.width : 'autofit'
    let realHeight = realScale != currScale ? item.height : 'autofit'
    let regex = new RegExp(`${itemEl}(\x20|{)`, 'gm')
    let isIgnored = regex.test(document.querySelector('#ignoreStyle').innerHTML)
    if (isIgnored) {
      continue
    }
    document.querySelector('#ignoreStyle').innerHTML += `\n${itemEl} { 
      transform: scale(${realScale})!important;
      transform-origin: 0 0;
      width: ${realWidth}!important;
      height: ${realHeight}!important;
    }`
    document.querySelector(
      '#ignoreStyle'
    ).innerHTML += `\n${itemEl} div ,${itemEl} span,${itemEl} a,${itemEl} * {
      font-size: ${realFontSize}px;
    }`
  }
}

